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<a name="MMIX_002dRegs"></a>
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Next: <a href="MMIX_002dPseudos.html#MMIX_002dPseudos" accesskey="n" rel="next">MMIX-Pseudos</a>, Previous: <a href="MMIX_002dSymbols.html#MMIX_002dSymbols" accesskey="p" rel="prev">MMIX-Symbols</a>, Up: <a href="MMIX_002dSyntax.html#MMIX_002dSyntax" accesskey="u" rel="up">MMIX-Syntax</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Register-names-1"></a>
<h4 class="subsubsection">9.28.3.3 Register names</h4>
<a name="index-register-names_002c-MMIX"></a>
<a name="index-MMIX-register-names"></a>

<p>Local and global registers are specified as &lsquo;<samp>$0</samp>&rsquo; to &lsquo;<samp>$255</samp>&rsquo;.
The recognized special register names are &lsquo;<samp>rJ</samp>&rsquo;, &lsquo;<samp>rA</samp>&rsquo;, &lsquo;<samp>rB</samp>&rsquo;,
&lsquo;<samp>rC</samp>&rsquo;, &lsquo;<samp>rD</samp>&rsquo;, &lsquo;<samp>rE</samp>&rsquo;, &lsquo;<samp>rF</samp>&rsquo;, &lsquo;<samp>rG</samp>&rsquo;, &lsquo;<samp>rH</samp>&rsquo;,
&lsquo;<samp>rI</samp>&rsquo;, &lsquo;<samp>rK</samp>&rsquo;, &lsquo;<samp>rL</samp>&rsquo;, &lsquo;<samp>rM</samp>&rsquo;, &lsquo;<samp>rN</samp>&rsquo;, &lsquo;<samp>rO</samp>&rsquo;,
&lsquo;<samp>rP</samp>&rsquo;, &lsquo;<samp>rQ</samp>&rsquo;, &lsquo;<samp>rR</samp>&rsquo;, &lsquo;<samp>rS</samp>&rsquo;, &lsquo;<samp>rT</samp>&rsquo;, &lsquo;<samp>rU</samp>&rsquo;,
&lsquo;<samp>rV</samp>&rsquo;, &lsquo;<samp>rW</samp>&rsquo;, &lsquo;<samp>rX</samp>&rsquo;, &lsquo;<samp>rY</samp>&rsquo;, &lsquo;<samp>rZ</samp>&rsquo;, &lsquo;<samp>rBB</samp>&rsquo;,
&lsquo;<samp>rTT</samp>&rsquo;, &lsquo;<samp>rWW</samp>&rsquo;, &lsquo;<samp>rXX</samp>&rsquo;, &lsquo;<samp>rYY</samp>&rsquo; and &lsquo;<samp>rZZ</samp>&rsquo;.  A leading
&lsquo;<samp>:</samp>&rsquo; is optional for special register names.
</p>
<p>Local and global symbols can be equated to register names and used in
place of ordinary registers.
</p>
<p>Similarly for special registers, local and global symbols can be used.
Also, symbols equated from numbers and constant expressions are allowed in
place of a special register, except when either of the options
<code>--no-predefined-syms</code> and <code>--fixed-special-register-names</code> are
specified.  Then only the special register names above are allowed for the
instructions having a special register operand; <code>GET</code> and <code>PUT</code>.
</p>



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